This invention relates to a method and apparatus for supporting video screens and more particularly to a retention mechanism for an audiovisual screen or a plurality of such screens placed in abutment to form a video display wall.
Audiovisual (A/V) systems used in amphitheaters, control rooms or large conference rooms may be separate systems which can be assembled and disassembled for movement between one location and another. Typically these types of audiovisual systems include a rear projection screen for viewing and an enclosure unit supporting the screen and placing the projector in proper alignment for projection of the video image onto a mirror which then directs the images onto the screen.
Often, there is a need for a large screen than can be provided by one audiovisual unit. Several units are then placed side by side for an enlarged viewing surface. However, due to the supporting structure and cabinetry around the screen of each audiovisual unit, there is a framing interruption between the screens of each unit resulting in a fragmentation of the projected image which disrupts viewing.
There is a need therefore for an audiovisual system in which the supporting structure of the audiovisual unit allows for multiple screens to be placed side by side resulting in a larger screen area with no apparent gaps or interruptions between screens, or ideally in the projected image itself, to give the appearance of one larger continuous screen.
Where an even larger image is required than can be obtained by placing two or more A/V units side-by-side, a video wall is constructed consisting of multiple screens arranged typically in a rectangular pattern of rows and columns of individual screens. This requires a framing system that allows the individual screens to be assembled together with minimal spacing between the adjacent edges of abutting screens and which can accommodate angular orientations between adjacent screens for a concave curvature of the video wall relative to the viewing audience if so desired.
One approach to the problem of framing a video wall is disclosed in U.S. Pat. No. 5,103,339 dates Apr. 7, 1992. The patented system includes front and rear brackets positioned at the front and back surfaces of the abutting screens adjacent to their vertical and horizontal edges, the brackets being held together by means of threaded fasteners passing between the abutting edges of the screens to connect the front and rear brackets together. This system requires the use of numerous discrete parts including the brackets and the threaded fasteners and requires considerable assembly time. Moreover, the front brackets have a substantial width highly visible to viewers that interrupts the continuity of the projected image, nor is the system adaptable for use in connection with discrete audiovisual units.
It is therefore an object of the present invention to provide a method and apparatus for supporting one or more rear projection screens in a manner intended to obviate and mitigate from the disadvantages of the prior art.
It is a further object of the present invention to provide a screen retaining mechanism that eliminates the gap between adjacent screens when placed in abutting relationship to one another.
It is a further object of the present invention to provide a framing and retention mechanism for video projection screens that minimizes the amount of assembly required to place the screens in close abutting relationship.
According to the present invention then, there is provided a system for retaining a video screen in a frame, comprising a video screen; frame means for supporting said video screen along at least a portion of the screen""s peripheral edges; and means for biasing said edges of said screen against said frame means to hold said screen in position relative to said frame means.